Variables: pH Substances: Acibenzolar-S-methyl (UELITFHSCLAHKR-UHFFFAOYSA-N) 1-(3-Chlorophenyl)-piperazin (VHFVKMTVMIZMIK-UHFFFAOYSA-N) 2-4-D (OVSKIKFHRZPJSS-UHFFFAOYSA-N) Keywords: MetFrag monitoring